Direct Detection Portals for Self-interacting Dark Matter

Understand

Dark matter self-interactions can affect the small scale structure of the Universe, reducing the central densities of dwarfs and low surface brightness galaxies in accord with observations.

• From a particle physics point of view, this points toward the existence of a 1-100 MeV particle in the dark sector that mediates self-interactions.
• Since mediator particles will generically couple to the Standard Model, direct detection experiments provide sensitive probes of self-interacting dark matter.
• We consider three minimal mechanisms for coupling the dark and visible sectors: photon kinetic mixing, Z boson mass mixing, and the Higgs portal.